The present invention relates to improvements in methods of making plastic bags or pouches from film, and more particularly to making shaped pouches with reclosable fastener strips along the top.
In the manufacture of bags and pouches, particularly those suited for the holding of foodstuffs, it is desirable to provide a pouch which has a sealed top to avoid contamination of the food product therein and to avoid escape of liquids or oils contained in the food product. A further desirable feature of the bag is to provide for greater usability in making the bag so that it can be opened and resealed. An optimum form of closure to satisfy these desirable objectives is to provide a rib and groove interlocking closure across the top of the finished pouch. The interlocking closure is such that it is initially backed up by a tamper-evident seal which generally constitutes a web extending between the sides of the interlocking rib and groove closure but which is frangible so as to be able to be broken when the bag is first used. To provide such a structure, establishes problems in manufacture.
The manufacture of reclosable bags should be conducted at a commercial pace or speed. The manufacturing operation must manufacture the bag, attach the closure and include the product within the bag in a single relatively high speed operation.